1. Field of the Invention
The present invention relates to a detection device assembly attached to a T-fitting of a conduit pipe, and more particularly to an anti-rotation arrangement for a detection device assembly that prevents rotation of the detection device relative to the T-fitting after attachment thereto. More specifically, the present invention relates to an anti-rotation arrangement that permits installation and removal of the detection device assembly without having to rotate the entire assembly.
2. Prior Art
Fire suppression systems are well known in the art and are used in residential and commercial buildings for detecting, suppressing and extinguishing fires through a system of sprinklers, fluid conduits and detection systems installed throughout the building. Normally, fire suppression systems comprise a system of sprinklers in communication with fluid conduits which are connected to a municipal water supply for supplying water to the sprinklers in order to extinguish fires inside the building. Fire suppression systems normally include detection devices for detecting changes in pressure and fluid flow within the fluid conduits when the sprinklers are activated during a fire in order to activate an alarm. In the prior art, detection devices were installed along the fluid conduits at T-fittings by engaging an integral union of the detection device to the T-fitting and rotating the entire device until it was fully engaged to the T-fitting in a fluid tight seal.
However, these type of detection devices had several drawbacks. Prior art detection devices, such as those which detect fluid flow, must have the device housing oriented correctly relative to the direction of fluid flow through the fluid conduit in order to accurately detect such flow. If the device housing is bumped or jarred during maintenance of the fire suppression system, the detection device could be inadvertently rotated and placed in the wrong orientation, thereby rendering it ineffective. Further, in residential fire suppression systems such detection devices are normally located inside a small space located between the walls of the residence which makes rotation and removal of the entire device for maintenance purposes impossible without first tearing out a section of the wall in order to properly access the device.
Accordingly, there is a need in the art for detection device assembly having an anti-rotation arrangement that prevents inadvertent rotation of the device housing relative to the T-fitting of a fluid conduit after installation of the device. In addition, there is a need in the art for an anti-rotation arrangement that permits installation and removal of the detection device within small spaces without having to rotate the entire device housing.
In brief summary, the present invention overcomes and substantially alleviates the deficiencies in the prior art by providing an anti-rotation arrangement for a detection device assembly for use in a fire suppression system. The anti-rotation arrangement of the present invention comprises a union, an adapter and a locking collar. The adapter includes a body having upper and lower portions and a passage formed therethrough for communication with the fluid pathway of the fluid conduit. In addition, the face of the lower portion of the adapter has radial teeth formed adjacent the outer circumference of the adapter, while the upper portion thereof is adapted for attachment to a housing of the detection device assembly. The locking collar is provided as a means for installing and removing the detection device assembly to the T-fitting without having to rotate the entire assembly. Specifically, the locking collar has an annular shape having distal and proximal openings with a passage formed between the openings. The interior surface of the passage includes internal threads which terminate at an inner shoulder formed adjacent the proximal opening. During assembly, the adapter is seated against the shoulder of the locking collar and secured to the housing of the detection device assembly such that the locking collar is freely rotatable between the housing and the adapter. Preferably, a union having top and bottom threaded portions and a shoulder formed therebetween is provided for attaching the detection device assembly to a T-fitting of a fluid conduit. The face of the top threaded portion of the union includes radial teeth formed adjacent the outer circumference of the face which are adapted to mate with the radial teeth of the adapter when the locking collar is secured to the union during engagement of the detection device assembly to the T-fitting.
To assemble, the adapter is inserted through the distal opening of the locking collar until the adapter abuts against the internal shoulder of the locking collar. The lower portion of the adapter is then secured to the underside of the device housing such that the locking collar freely rotates between the adapter and the device housing, but is securely engaged therebetween. Once the adapter is secured to the device housing, the bottom threaded portion of the union is engaged to the T-fitting by rotating the bottom threaded portion into secure engagement with internal threads formed adjacent the opening of the T-fitting. The user then engages the internal threads of the locking collar with the external threads of the upper threaded portion of the union by rotating the locking collar in one direction until the radial teeth of the adapter mate with the radial teeth of the union and a secure engagement is achieved between the locking collar and the union without rotation of the device housing. Once the detection device assembly is secured to the T-fitting, the mating of the radial teeth of the union and adapter effectively prevents rotation of the device housing relative to the T-fitting after installation.
In an alternative embodiment, the bottom portion of the union has a generally smooth cylindrical configuration rather than having the external threads found on the preferred embodiment so that T-fittings which do not have internal threads may be engaged by the union. An adhesive or other suitable bonding material is applied to the lower portion of the union for providing a sealing engagement when the union is inserted inside the T-fitting.
Accordingly, the primary object of the present invention is to provide an anti-rotation arrangement for a detection device assembly that prevents rotation of the device housing after installation.
Another object of the present invention is to provide an anti-rotation arrangement that permits installation and removal of the detection device assembly in relatively small spaces without having to rotate the device housing.
A further object of the present invention is to provide an anti-rotation arrangement that may be attached to T-fittings of fluid conduits that do not have internal threads.
Another further object of the present invention is to provide a simple and cost-effective method of installing and removing a detection device assembly to different types of T-fittings.
These and other objects of the present invention are realized in the preferred embodiment of the present invention, described by way of example and not by way of limitation, which provides for an anti-rotation arrangement for preventing rotation of the detection device assembly relative to a T-fitting of a fluid conduit.
Additional objects, advantages and novel features of the invention will be set forth in the description which follows, and will become apparent to those skilled in the art upon examination of the following more detailed description and drawings in which like elements of the invention are similarly numbered throughout.